[deliverable/linux.git] / drivers / base / power / common.c

/*
 * drivers/base/power/common.c - Common device power management code.
 *
 * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
 *
 * This file is released under the GPLv2.
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/pm_clock.h>
#include <linux/acpi.h>
#include <linux/pm_domain.h>

/**
 * dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
 * @dev: Device to handle.
 *
 * If power.subsys_data is NULL, point it to a new object, otherwise increment
 * its reference counter.  Return 0 if new object has been created or refcount
 * increased, otherwise negative error code.
 */
int dev_pm_get_subsys_data(struct device *dev)
{
	struct pm_subsys_data *psd;

	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
	if (!psd)
		return -ENOMEM;

	spin_lock_irq(&dev->power.lock);

	if (dev->power.subsys_data) {
		dev->power.subsys_data->refcount++;
	} else {
		spin_lock_init(&psd->lock);
		psd->refcount = 1;
		dev->power.subsys_data = psd;
		pm_clk_init(dev);
		psd = NULL;
	}

	spin_unlock_irq(&dev->power.lock);

	/* kfree() verifies that its argument is nonzero. */
	kfree(psd);

	return 0;
}
EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);

/**
 * dev_pm_put_subsys_data - Drop reference to power.subsys_data.
 * @dev: Device to handle.
 *
 * If the reference counter of power.subsys_data is zero after dropping the
 * reference, power.subsys_data is removed.
 */
void dev_pm_put_subsys_data(struct device *dev)
{
	struct pm_subsys_data *psd;

	spin_lock_irq(&dev->power.lock);

	psd = dev_to_psd(dev);
	if (!psd)
		goto out;

	if (--psd->refcount == 0)
		dev->power.subsys_data = NULL;
	else
		psd = NULL;

 out:
	spin_unlock_irq(&dev->power.lock);
	kfree(psd);
}
EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);

/**
 * dev_pm_domain_attach - Attach a device to its PM domain.
 * @dev: Device to attach.
 * @power_on: Used to indicate whether we should power on the device.
 *
 * The @dev may only be attached to a single PM domain. By iterating through
 * the available alternatives we try to find a valid PM domain for the device.
 * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
 * should be assigned by the corresponding attach function.
 *
 * This function should typically be invoked from subsystem level code during
 * the probe phase. Especially for those that holds devices which requires
 * power management through PM domains.
 *
 * Callers must ensure proper synchronization of this function with power
 * management callbacks.
 *
 * Returns 0 on successfully attached PM domain or negative error code.
 */
int dev_pm_domain_attach(struct device *dev, bool power_on)
{
	int ret;

	ret = acpi_dev_pm_attach(dev, power_on);
	if (ret)
		ret = genpd_dev_pm_attach(dev);

	return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_domain_attach);

/**
 * dev_pm_domain_detach - Detach a device from its PM domain.
 * @dev: Device to attach.
 * @power_off: Used to indicate whether we should power off the device.
 *
 * This functions will reverse the actions from dev_pm_domain_attach() and thus
 * try to detach the @dev from its PM domain. Typically it should be invoked
 * from subsystem level code during the remove phase.
 *
 * Callers must ensure proper synchronization of this function with power
 * management callbacks.
 */
void dev_pm_domain_detach(struct device *dev, bool power_off)
{
	if (dev->pm_domain && dev->pm_domain->detach)
		dev->pm_domain->detach(dev, power_off);
}
EXPORT_SYMBOL_GPL(dev_pm_domain_detach);
Commit	Line	Data
ef27bed1 RW	1	/*
	2	* drivers/base/power/common.c - Common device power management code.
	3	*
	4	* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
	5	*
	6	* This file is released under the GPLv2.
	7	*/
	8
ef27bed1	9	#include <linux/kernel.h>
51990e82	10	#include <linux/device.h>
aaf19544	11	#include <linux/export.h>
ef27bed1	12	#include <linux/slab.h>
b5e8d269	13	#include <linux/pm_clock.h>
46420dd7 UH	14	#include <linux/acpi.h>
46420dd7 UH	15	#include <linux/pm_domain.h>
ef27bed1 RW	16
	17	/**
	18	* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
	19	* @dev: Device to handle.
	20	*
	21	* If power.subsys_data is NULL, point it to a new object, otherwise increment
766bb53c UH	22	* its reference counter. Return 0 if new object has been created or refcount
766bb53c UH	23	* increased, otherwise negative error code.
ef27bed1 RW	24	*/
	25	int dev_pm_get_subsys_data(struct device *dev)
	26	{
	27	struct pm_subsys_data *psd;
ef27bed1 RW	28
	29	psd = kzalloc(sizeof(*psd), GFP_KERNEL);
	30	if (!psd)
	31	return -ENOMEM;
	32
	33	spin_lock_irq(&dev->power.lock);
	34
	35	if (dev->power.subsys_data) {
	36	dev->power.subsys_data->refcount++;
	37	} else {
	38	spin_lock_init(&psd->lock);
	39	psd->refcount = 1;
	40	dev->power.subsys_data = psd;
	41	pm_clk_init(dev);
	42	psd = NULL;
ef27bed1 RW	43	}
	44
	45	spin_unlock_irq(&dev->power.lock);
	46
	47	/* kfree() verifies that its argument is nonzero. */
	48	kfree(psd);
	49
77254950	50	return 0;
ef27bed1 RW	51	}
	52	EXPORT_SYMBOL_GPL(dev_pm_get_subsys_data);
	53
	54	/**
	55	* dev_pm_put_subsys_data - Drop reference to power.subsys_data.
	56	* @dev: Device to handle.
	57	*
	58	* If the reference counter of power.subsys_data is zero after dropping the
1e95e3b2	59	* reference, power.subsys_data is removed.
ef27bed1	60	*/
1e95e3b2	61	void dev_pm_put_subsys_data(struct device *dev)
ef27bed1 RW	62	{
ef27bed1 RW	63	struct pm_subsys_data *psd;
ef27bed1 RW	64
	65	spin_lock_irq(&dev->power.lock);
	66
	67	psd = dev_to_psd(dev);
d5e1670a	68	if (!psd)
ef27bed1	69	goto out;
ef27bed1	70
1e95e3b2	71	if (--psd->refcount == 0)
ef27bed1	72	dev->power.subsys_data = NULL;
1e95e3b2	73	else
d5e1670a	74	psd = NULL;
ef27bed1 RW	75
	76	out:
	77	spin_unlock_irq(&dev->power.lock);
d5e1670a	78	kfree(psd);
ef27bed1 RW	79	}
ef27bed1 RW	80	EXPORT_SYMBOL_GPL(dev_pm_put_subsys_data);
46420dd7 UH	81
	82	/**
	83	* dev_pm_domain_attach - Attach a device to its PM domain.
	84	* @dev: Device to attach.
	85	* @power_on: Used to indicate whether we should power on the device.
	86	*
	87	* The @dev may only be attached to a single PM domain. By iterating through
	88	* the available alternatives we try to find a valid PM domain for the device.
	89	* As attachment succeeds, the ->detach() callback in the struct dev_pm_domain
	90	* should be assigned by the corresponding attach function.
	91	*
	92	* This function should typically be invoked from subsystem level code during
	93	* the probe phase. Especially for those that holds devices which requires
	94	* power management through PM domains.
	95	*
	96	* Callers must ensure proper synchronization of this function with power
	97	* management callbacks.
	98	*
	99	* Returns 0 on successfully attached PM domain or negative error code.
	100	*/
	101	int dev_pm_domain_attach(struct device *dev, bool power_on)
	102	{
	103	int ret;
	104
	105	ret = acpi_dev_pm_attach(dev, power_on);
	106	if (ret)
	107	ret = genpd_dev_pm_attach(dev);
	108
	109	return ret;
	110	}
	111	EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
	112
	113	/**
	114	* dev_pm_domain_detach - Detach a device from its PM domain.
	115	* @dev: Device to attach.
	116	* @power_off: Used to indicate whether we should power off the device.
	117	*
	118	* This functions will reverse the actions from dev_pm_domain_attach() and thus
	119	* try to detach the @dev from its PM domain. Typically it should be invoked
	120	* from subsystem level code during the remove phase.
	121	*
	122	* Callers must ensure proper synchronization of this function with power
	123	* management callbacks.
	124	*/
	125	void dev_pm_domain_detach(struct device *dev, bool power_off)
	126	{
	127	if (dev->pm_domain && dev->pm_domain->detach)
	128	dev->pm_domain->detach(dev, power_off);
	129	}
	130	EXPORT_SYMBOL_GPL(dev_pm_domain_detach);